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/*******************************************************************************
* Copyright (c) 2000, 2009 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.core.util;
/**
* Hashtable of {Object[] --> Object }
*/
public final class HashtableOfArrayToObject implements Cloneable {
// to avoid using Enumerations, walk the individual tables skipping nulls
public Object[][] keyTable;
public Object[] valueTable;
public int elementSize; // number of elements in the table
int threshold;
public HashtableOfArrayToObject() {
this(13);
}
public HashtableOfArrayToObject(int size) {
this.elementSize = 0;
this.threshold = size; // size represents the expected number of elements
int extraRoom = (int) (size * 1.75f);
if (this.threshold == extraRoom)
extraRoom++;
this.keyTable = new Object[extraRoom][];
this.valueTable = new Object[extraRoom];
}
@Override
public Object clone() throws CloneNotSupportedException {
HashtableOfArrayToObject result = (HashtableOfArrayToObject) super.clone();
result.elementSize = this.elementSize;
result.threshold = this.threshold;
int length = this.keyTable.length;
result.keyTable = new Object[length][];
System.arraycopy(this.keyTable, 0, result.keyTable, 0, length);
length = this.valueTable.length;
result.valueTable = new Object[length];
System.arraycopy(this.valueTable, 0, result.valueTable, 0, length);
return result;
}
public boolean containsKey(Object[] key) {
int length = this.keyTable.length;
int index = hashCode(key) % length;
int keyLength = key.length;
Object[] currentKey;
while ((currentKey = this.keyTable[index]) != null) {
if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key))
return true;
if (++index == length) {
index = 0;
}
}
return false;
}
public Object get(Object[] key) {
int length = this.keyTable.length;
int index = hashCode(key) % length;
int keyLength = key.length;
Object[] currentKey;
while ((currentKey = this.keyTable[index]) != null) {
if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key))
return this.valueTable[index];
if (++index == length) {
index = 0;
}
}
return null;
}
public int getIndex(Object[] key) {
int length = this.keyTable.length;
int index = hashCode(key) % length;
int keyLength = key.length;
Object[] currentKey;
while ((currentKey = this.keyTable[index]) != null) {
if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key))
return index;
if (++index == length) {
index = 0;
}
}
return -1;
}
public Object[] getKey(Object[] key, int keyLength) {
int length = this.keyTable.length;
int index = hashCode(key, keyLength) % length;
Object[] currentKey;
while ((currentKey = this.keyTable[index]) != null) {
if (currentKey.length == keyLength && Util.equalArrays(currentKey, key, keyLength))
return currentKey;
if (++index == length) {
index = 0;
}
}
return null;
}
private int hashCode(Object[] element) {
return hashCode(element, element.length);
}
private int hashCode(Object[] element, int length) {
int hash = 0;
for (int i = length-1; i >= 0; i--)
hash = Util.combineHashCodes(hash, element[i].hashCode());
return hash & 0x7FFFFFFF;
}
public Object put(Object[] key, Object value) {
int length = this.keyTable.length;
int index = hashCode(key) % length;
int keyLength = key.length;
Object[] currentKey;
while ((currentKey = this.keyTable[index]) != null) {
if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key))
return this.valueTable[index] = value;
if (++index == length) {
index = 0;
}
}
this.keyTable[index] = key;
this.valueTable[index] = value;
// assumes the threshold is never equal to the size of the table
if (++this.elementSize > this.threshold)
rehash();
return value;
}
public Object removeKey(Object[] key) {
int length = this.keyTable.length;
int index = hashCode(key) % length;
int keyLength = key.length;
Object[] currentKey;
while ((currentKey = this.keyTable[index]) != null) {
if (currentKey.length == keyLength && Util.equalArraysOrNull(currentKey, key)) {
Object value = this.valueTable[index];
this.elementSize--;
this.keyTable[index] = null;
this.valueTable[index] = null;
rehash();
return value;
}
if (++index == length) {
index = 0;
}
}
return null;
}
private void rehash() {
HashtableOfArrayToObject newHashtable = new HashtableOfArrayToObject(this.elementSize * 2); // double the number of expected elements
Object[] currentKey;
for (int i = this.keyTable.length; --i >= 0;)
if ((currentKey = this.keyTable[i]) != null)
newHashtable.put(currentKey, this.valueTable[i]);
this.keyTable = newHashtable.keyTable;
this.valueTable = newHashtable.valueTable;
this.threshold = newHashtable.threshold;
}
public int size() {
return this.elementSize;
}
@Override
public String toString() {
StringBuffer buffer = new StringBuffer();
Object[] element;
for (int i = 0, length = this.keyTable.length; i < length; i++)
if ((element = this.keyTable[i]) != null) {
buffer.append('{');
for (int j = 0, length2 = element.length; j < length2; j++) {
buffer.append(element[j]);
if (j != length2-1)
buffer.append(", "); //$NON-NLS-1$
}
buffer.append("} -> "); //$NON-NLS-1$
buffer.append(this.valueTable[i]);
if (i != length-1)
buffer.append('\n');
}
return buffer.toString();
}
}
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